Determine whether the following relation is a function.
{(3,7), (3,8), (3,-2), (3.,1)}
a) it is a function because the ordered pairs all have the same x-value.
b) it is not a function because there are multiple y-values paired with a single x-value.
c) it is a function because none of the ordered pairs have the same y-value.
d) it is not a function because none of the ordered pairs have the same y-value.